The moderate Tamil National Alliance (TNA) said the report, commissioned by UN Secretary General Ban Ki-moon, amounted to "irrefutable confirmation" of atrocities during the final stages of fighting in 2009.
"We welcome the recommendations made by the panel and trust that they will be honestly implemented," the alliance said in a statement.
The UN report, published in a pro-government newspaper in Colombo on Saturday, detailed "credible allegations" which, if proven, indicate a wide range of violations by both the government and the rebels.
The panel appointed by Ban has recommended that an independent commission be appointed to investigate alleged atrocities.
The Sri Lankan government has already rejected the UN report as flawed and biased.
buy zoloft online buy zoloft online no prescription
The island strongly protested when Ban appointed the advisory panel in June 2010 and refused to allow members to visit the island.
President Mahinda Rajapakse has urged supporters to turn this year's May Day rallies into a sho